Heretofore, magnetic recording media in the form of tapes or disks have been widely used for informational storage, due mainly to their massive storage capacities and cost effectiveness. To interact with these magnetic recording media, magnetic transducers are commonly employed to perform the tasks.
A typical thin-film magnetic transducer comprises an inductive coil sandwiched between two magnetic poles. The two magnetic poles come into direct contact with each other at one end, and form a narrow transducing gap at another end. During the data writing mode, electrical current with information passes through the inductive coil. The current carrying coil induces magnetic flux into the magnetic poles. The induced magnetic flux flow through the poles along the magnetic path, reaching the transducing gap and magnetizes a moving recording medium disposed close by. During the data reading mode, magnetic flux emanating from the recorded medium is sensed by the transducing gap. The magnetic flux flows along the magnetic path defined by the two magnetic poles and induces electrical current in the inductive coil. The induced current in the coil corresponds to the data content stored in the recording medium.
The tendency in present day technology is to fabricate recording media with high data capacities and of smaller size. It is known that with such characteristics, the recorded data tracks emanate weaker magnetic flux. Signals sensed by the magnetic transducer are correspondingly diminished. Consequently, a conventional magnetic read head is susceptible to pick up undesirable noise signal. The noise signal adversely affects the data signal, thereby degrading the overall signal-to-noise ratio (SNR) of the magnetic head. Higher data recording density per track coupled with higher rotating velocity of the disk demand higher bandwidth capability from the magnetic head. With a large inductive head, the prior art transducers may not be responsive enough to operate in high frequency environments.
To reduce such problems, various techniques have been suggested. One such technique is to increase the number of coil windings in the magnetic head in an effort to enhance the signal sensing capability. The problem with this approach is that the inductance of the magnetic head is also accordingly increased. As is well known in the art, an increase in inductance of the coil correspondingly results in an increase in reactance of the magnetic head, and consequently slows the response time. To compensate for the increase in inductance, attempts have been made to modify the geometrical feature of the magnetic head by reducing the yoke width, increasing the pole-to-pole separations, or minimizing the throat height of the magnetic head. None of these techniques have demonstrated any satisfactory working results.